1. Field of the Invention
The present invention relates to an apparatus for hinging together the housings of foldable devices, and particularly to an apparatus for hinging together the housings of a foldable mobile phone.
2. Description of Related Art
Portable radiotelephones having two housings joined by a type of hinge that allows the housings to fold upon one another are known in the art. Some such folding radiotelephones have most of the electronics in one housing, called the main housing, and fewer electronics in the other housing, called the cover. Other such folding radiotelephones have all the electronics in the body with the cover serving only to cover the keypad or keypad and display of the phone.
TW Pat. No. 411069 discloses a hinge assembly 40 as shown in FIGS. 5–6. A rotating shaft 41 is respectively inserted through a washer 42, a stationary cam 43, a sliding cam 44, a spring 45, and a fixing member 46. An elastic ring clip 47 fitted to an engaging groove (not labeled) of the shaft 41 is locked to a deformed hole (not labeled) of the fixing member 46 by being mounted into the hole at an inside thereof. The shaft 41 is thereby fixed such that the shaft 41 does not come off the fixing member 46 and the fixing member 46 is rotated along with the shaft 41. A ring 48 is fitted to another engaging groove (not labeled) of the shaft 41. Furthermore, the fixing member 46 is fastened in and rotated along with the cover 50, and the stationary cam 43 is fixed in the main body of the mobile phone. The sliding cam 44 is rotated along with the shaft 41 and can linearly slide along the shaft 41. When the cover 50 is rotated, the fixing member 46 and the shaft 41 are rotated along with the cover, and the sliding cam 44 engages with the stationary cam 43 to retain the cover 50 in an opened or closed position. However, during cover rotation, the shaft 41 suffers a torsional force, so that the shaft 41 is in danger of being broken or damaged. Furthermore, the hinge assembly 40 is complex, and is not convenient to assemble in a limited retaining space of the mobile phone.
Therefore, an improved structure of a hinge assembly is desired which overcomes the disadvantages of the prior art.